Roulette: how they prevent you breaking the bank

In 1891, an English roulette player named Charles de Ville Wells 'broke the bank' at Monaco's casino not once but six times in three days. By doubling his stake every time he lost, and then winning, he turned an initial 10,000 francs into a million. He died penniless in 1926, but he inspired a popular song, The Man who Broke the Bank at Monte Carlo, and a potent myth: that it is possible to devise a system that can beat the roulette wheel.

There is certainly a seductive magic about roulette. It is easy to play. It has an aura of sophistication and drama. And, occasionally, there are astonishing runs of winning numbers - Number 10 came up six times in a row at the El San Juan Hotel, Puerto Rico, on July 9, 1959.

Roulette can give the gambler the strong impression that character and intelligence ought to pay off, so long as he can devise a suitable system. Usually, any system involves spotting a pattern. The theory, in its simplest form, goes like this: in 100 tosses a coin is likely to come up heads about 50 times. If it comes up tails 20 times in the first 20 tosses - so the theory goes - then there is a higher chance of it 'correcting' itself by coming up heads the next time. Any roulette table has its avid watchers trying to spot a 'trend' - such as the black numbers coming up several times in succession - in order to bet against it. Sometimes, gamblers call this The Law of Equilibrium', or the 'doctrine of the maturity of the chances'.

In fact, there is no such law. A more accurate name is the 'Monte Carlo fallacy'. The odds remain the same for every throw, whatever the previous run. The truth is that it simply is not possible to beat the house legally, for several reasons.

First, the wheel itself gives a built-in advantage to the house. All bets are placed on one or more of the 36 numbers, or a variety of combinations of them - odd or even, black or red, high or low. The payouts are calculated as if the ball had a 35:1 chance of landing on each of the numbers.

But there are, in fact, one or two additional 'boxes' - 0 on a European wheel and 0 and 00 on an American wheel. This gives the bank an advantage of from 1.76 per cent up to 7.89 per cent, depending on which wheel is used and which bets have been placed.
Even the 'Martingale' system - doubling up your bets every time you lose - adopted by Mr Wells will eventually fall victim to this built-in advantage.

There are other advantages possessed by the house. In a betting match between two otherwise equal rivals, the one with more money almost always wipes out the other, simply because he can go on betting longer. The house can always send for more money, while most gamblers at some point decide to call it quits, and walk away losers. Then there are house rules by which the croupier pays out fractionally less than the odds dictate - for example, by rounding down figures in favour of the house.

The gambler himself often makes mistakes, no matter how well he knows the odds or his system. Since there are 12 different ways to place bets, combining black or red, odd or even, individual numbers and any number of numbers up to 12, all governed by their own odds, it is easy to become confused.

In theory, it should be possible to devise a computer system that predicted the straight position of the ball on landing. The technology has existed for some years to sense the movement of the ball, its spin and velocity, and apply complex mathematical principles to predict its final position.

Gamblers in the USA have tried to better the odds by using computers to analyse play statistically, strapping computers to their bodies, or even hiding them in their shoes.
However, the casino security guards are easily made suspicious of anyone communicating by radio, or suspected of concealing computer equipment. Although this kind of system is not illegal in the USA, the participants would be encouraged to leave the casino and not return.

To prevent the return of unwanted gamblers, some European casinos employ men called physiognomists, who have photographic memories for faces and names. People known to be big winners, whatever their system, may be refused entry to the casino.